一个考虑浅层地下水位埋深的降雨物理入渗模型

基于经典Green-Ampt入渗模型,建立了考虑任意降雨强度下浅层地下水位埋深的降雨物理入渗模型.针对4种不同渗透性质的土样,将此模型的解析解与数值模拟结果进行对比分析,结果表明:所建的降雨入渗物理模型及其数值解的最大积水时差仅为0.274 h,最大相对累积入渗量误差仅为3.204%,验证了该修正模型的合理性.同时以砂质壤土为例,利用该模型分析不同地下水位埋深对降雨入渗的影响.分析表明:雨水入渗速率、累积入渗量以及积水时间受地下水位埋深的影响较小,而湿润锋深度随着降雨历时的增加受其影响逐渐明显.

A rainfall infiltration physical model considering the depth of water table

On the basis of the traditional Green-Ampt infiltration model, the extended infiltration model considering the depths of water table is established. Four different types of soil textures are adopted to obtain the corresponding analytical solutions and numerical solutions. The results show that the error of the ponding time is only 0.274h and the error of relatively accumulative infiltration is 3.204%, which show that the proposed model is quite reasonable. Take the sandy loam for example, we use the validated model to analyze how the depth of the water table affects the rainwater infiltrate into unsaturated soil, the analysis shows that the infiltration rate, cumulative infiltration and the ponding time are less susceptible to the depth of water table. However, with the duration of the rainfall increase, the depth of wetting front is influenced more obviously.